#ifdef GL_FRAGMENT_PRECISION_HIGH
	precision highp float;
#else
	precision mediump float;
#endif


uniform sampler2D s_texture;

uniform vec2 texcoordOffset;

varying vec4 vertColor;
varying vec2 aVertexUVs_;

void main(){

  //float FXAA_SPAN_MAX = 8.0;
  //float FXAA_REDUCE_MUL = 1.0/8.0;
  //float FXAA_REDUCE_MIN = (1.0/128.0);
  
  
  float FXAA_SPAN_MAX = 8.0;
  float FXAA_REDUCE_MUL = 1.0/8.0;
  float FXAA_REDUCE_MIN = (1.0/512.0);

  vec3 rgbNW = texture2D(s_texture, aVertexUVs_.xy + (vec2(-1.0, -1.0) * texcoordOffset)).xyz;
  vec3 rgbNE = texture2D(s_texture, aVertexUVs_.xy + (vec2(+1.0, -1.0) * texcoordOffset)).xyz;
  vec3 rgbSW = texture2D(s_texture, aVertexUVs_.xy + (vec2(-1.0, +1.0) * texcoordOffset)).xyz;
  vec3 rgbSE = texture2D(s_texture, aVertexUVs_.xy + (vec2(+1.0, +1.0) * texcoordOffset)).xyz;
  vec3 rgbM  = texture2D(s_texture, aVertexUVs_.xy).xyz;
	
  //vec3 luma = vec3(0.299, 0.587, 0.114);
  vec3 luma = vec3(0.0, 1.0, 0.0);
  float lumaNW = dot(rgbNW, luma);
  float lumaNE = dot(rgbNE, luma);
  float lumaSW = dot(rgbSW, luma);
  float lumaSE = dot(rgbSE, luma);
  float lumaM  = dot( rgbM, luma);
	
  float lumaMin = min(lumaM, min(min(lumaNW, lumaNE), min(lumaSW, lumaSE)));
  float lumaMax = max(lumaM, max(max(lumaNW, lumaNE), max(lumaSW, lumaSE)));

	
  vec2 dir;
  dir.x = -((lumaNW + lumaNE) - (lumaSW + lumaSE));
  dir.y =  ((lumaNW + lumaSW) - (lumaNE + lumaSE));
	
  float dirReduce = max((lumaNW + lumaNE + lumaSW + lumaSE) * (0.25 * FXAA_REDUCE_MUL), FXAA_REDUCE_MIN);
	
  float rcpDirMin = 1.0/(min(abs(dir.x), abs(dir.y)) + dirReduce);
  
	
  dir = min(vec2(FXAA_SPAN_MAX,  FXAA_SPAN_MAX), 
        max(vec2(-FXAA_SPAN_MAX, -FXAA_SPAN_MAX), dir * rcpDirMin)) * texcoordOffset;
		
  vec3 rgbA = (1.0/2.0) * (
              texture2D(s_texture, aVertexUVs_.xy + dir * (1.0/3.0 - 0.5)).xyz +
              texture2D(s_texture, aVertexUVs_.xy + dir * (2.0/3.0 - 0.5)).xyz);
  vec3 rgbB = rgbA * (1.0/2.0) + (1.0/4.0) * (
              texture2D(s_texture, aVertexUVs_.xy + dir * (0.0/3.0 - 0.5)).xyz +
              texture2D(s_texture, aVertexUVs_.xy + dir * (3.0/3.0 - 0.5)).xyz);
  float lumaB = dot(rgbB, luma);
  
      	
  if((lumaB < lumaMin) || (lumaB > lumaMax)){
    gl_FragColor.xyz=rgbA;
  } else {
    gl_FragColor.xyz=rgbB;
  }
  gl_FragColor.a = 1.0;
    
  
  
  
  /*
  
  vec3 rgbN = texture2D(s_texture, aVertexUVs_.xy + (vec2(0.0, -1.0) * texcoordOffset)).xyz;
  vec3 rgbS = texture2D(s_texture, aVertexUVs_.xy + (vec2(0.0, 1.0) * texcoordOffset)).xyz;
  vec3 rgbW = texture2D(s_texture, aVertexUVs_.xy + (vec2(-1.0, 0.0) * texcoordOffset)).xyz;
  vec3 rgbE = texture2D(s_texture, aVertexUVs_.xy + (vec2(1.0, 0.0) * texcoordOffset)).xyz;
  vec3 rgbNW = texture2D(s_texture, aVertexUVs_.xy + (vec2(-1.0, -1.0) * texcoordOffset)).xyz;
  vec3 rgbNE = texture2D(s_texture, aVertexUVs_.xy + (vec2(+1.0, -1.0) * texcoordOffset)).xyz;
  vec3 rgbSW = texture2D(s_texture, aVertexUVs_.xy + (vec2(-1.0, +1.0) * texcoordOffset)).xyz;
  vec3 rgbSE = texture2D(s_texture, aVertexUVs_.xy + (vec2(+1.0, +1.0) * texcoordOffset)).xyz;
  vec3 rgbM  = texture2D(s_texture, aVertexUVs_.xy).xyz;
  
  vec3 luma = vec3(0.299, 0.587, 0.114);
  float lumaN = dot(rgbN, luma);
  float lumaS = dot(rgbS, luma);
  float lumaW = dot(rgbW, luma);
  float lumaE = dot(rgbE, luma);
  float lumaNW = dot(rgbNW, luma);
  float lumaNE = dot(rgbNE, luma);
  float lumaSW = dot(rgbSW, luma);
  float lumaSE = dot(rgbSE, luma);
  float lumaM  = dot( rgbM, luma);
  
  float diffNS = abs(lumaN - lumaS);
  float diffWE = abs(lumaW - lumaE);
  float diffNWSE = abs(lumaNW - lumaSE);
  float diffNESW = abs(lumaNE - lumaSW);
  
  float I = abs(diffNS) + abs(diffWE) + abs(diffNWSE) + abs(diffNESW);
  
  float inv_maxDiff = 1.0/max(diffNS, max(diffWE, max(diffNWSE, diffNESW)));
  diffNS *= (1.0/8.0)*inv_maxDiff;
  diffWE *= (1.0/8.0)*inv_maxDiff;
  diffNWSE *= (0.69/8.0)*inv_maxDiff;
  diffNESW *= (0.69/8.0)*inv_maxDiff;
  
  float k = 1.0 - (diffNS + diffWE + diffNWSE + diffNESW);
  
  
  vec3 mid = k * rgbM + diffNS * (rgbN + rgbS) + diffWE * (rgbW + rgbE) + diffNWSE * (rgbNW + rgbSE) + diffNESW * (rgbNE + rgbSW);
  
  if(I < 0.1)
	gl_FragColor = vec4(mid, 1.0);
  else
	gl_FragColor = vec4(mid, 1.0);
  
  */
  

}